Bathtubs, bathtub and shower enclosures, shower stalls, basins, and the like, made of a synthetic resinous material, are known and have become increasingly popular due, among other things, to their light weight, ease of installation, and easy maintenance. One such type of resinous composite-shaped is comprised of a relatively thin gel top coat having a thermoset polyester, a supporting layer underneath the top coat made of a chopped glass fiber-filled or reinforced thermoset polyester, an intermediate layer underneath the supporting layer made of a polyurethane foam containing no reinforcing fibers, and a bottom layer underneath the intermediate layer made of a chopped glass fiber-reinforced thermoset polyester.
While these resinous composite-shaped articles are very useful and satisfactory, they suffer from a difficult manufacturing process used to produce the article. This composite article is made by first depositing the gel top coat layer on the outer surface of a mold, then depositing the supporting layer onto the gel coat layer, followed by depositing the intermediate layer on the supporting layer, and finally depositing the bottom layer on the intermediate layer. Since the gel top coat layer is quite thin and thus susceptible to puncture, deformation, and other damage, the supporting layer must be free of voids, air-pockets, and the like. However, the fiber glass filled thermosettable polyester supporting layer, as deposited by spraying, generally may not be free of voids, air pockets, and the like. These imperfections must be removed from the polyester resin before the thermosettable polyester resin is cured. A roller may be used to pass over the glass-filled thermosettable polyester deposit to remove any voids, airholes, and the like present therein. However, this is a rather time consuming and labor intensive procedure, particularly if the composite article is of a complex shape or form.
Each tub or shower has a drain in a drain area that must be of sufficient strength to support a user. Bathing vessels may be manufactured from a variety of different materials, such as plastic materials. Plastic bathing vessels, however, must meet certain minimum performance requirements. For instance, the American National Standards Institute (ANSI) sets forth minimum physical requirements and testing methods for plastic bathtub and shower units. A bathing vessel that meets the requirements is approved for use in homes, buildings or other structures as a plumbing fixture.